Proposal for Determining the Electromagnetic Form Factor of the Pion

The possibility of measuring the electromagnetic form factor of the pion by extrapolation of the cross section for e^-+p→n+π⁺+e^- has been investigated. The method is based on the existence of a pole in the pion-electroproduction scattering amplitude as a function of the invariant momentum-transfer of the nucleon. The residue of this pole is the pion form factor multiplied by a known coefficient. Since the pole lies slightly outside the physical region of the invariant momentum transfer, an extrapolation of the experimental data is required. An approximate calculation of the pion electroproduction cross section has been made in order to estimate the experimental accuracy necessary for a significant extrapolation. Accuracy is required which is an order of magnitude better than that achieved at present in similar experiments.